A silent heart attack, also known as silent myocardial ischemia, is a heart attack with either no symptoms or minimal, unrecognizable symptoms. The presence of a silent heart attack is a strong predictor of mortality.

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What is a silent heart attack?

A silent heart attack is a condition of reduced blood flow to the heart due to the accumulation of plaque in the arteries. The condition often occurs without causing typical heart attack symptoms, such as chest pain or discomfort, nausea and sweating, and shortness of breath. The condition is associated with 70-80% of transient ischemic episodes. 1   

Coronary artery disease is a major risk factor for silent heart attack, although people without a history of coronary artery disease can also be affected by the condition. 2   

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Silent heart attack symptoms lack the intensity of classic heart attack symptoms. In other words, the symptoms are so mild and brief that they are often mistaken for a regular discomfort or another less serious problem, such as heartburn, gastric reflux, indigestion, or fatigue due to work pressure or lack of sleep. 3

The location of the pain is another vital factor that is often misunderstood. Unlike a classic heart attack wherein a sharp pain appears on the left side of the chest, a silent heart attack may trigger a mild pain in the center of the chest. 3

In some cases, a silent heart attack occurs without any chest pain, and thus, patients suffering from the condition do not seek medical attention in a timely manner. All these factors contribute to the risk of missing the warning signs and subsequently increase the risk of morbidity and mortality. 3

What are the symptoms of a silent heart attack?

Silent heart attack patients may experience mild symptoms or no symptoms at all.

Unlike sudden and intense chest pain felt in classical heart attacks, a silent heart attack is associated with mild pain or discomfort in the center of the chest. People may also feel pressure, squeezing, or fullness in the chest. These symptoms typically appear slowly and subsequently go away and come back. 4

Apart from the chest, people with silent heart attacks may experience mild pain or discomfort in the arms, back, neck, jaw, or stomach. Shortness of breath and dizziness are common symptoms of a silent heart attack that may occur with or without chest pain. 4

Here are signs that you could be having a ‘silent’ heart attack

People with silent heart attacks may experience nausea, vomiting, and cold sweat. These symptoms are very similar to those that occur in viral infections and, thus, should be monitored carefully and attentively. 4

What are the risk factors of a silent heart attack?

The most common risk factor of silent heart attack is coronary artery disease. Accumulation of cholesterol-rich plaque in coronary arteries can restrict blood flow to the heart, which in turn can increase the risk of silent heart attack. 1

Diabetes is another major risk factor for silent heart attack. Cardiac autonomic dysfunction, which involves pain receptors, afferent neurons, or higher brain areas, is significantly associated with the development of diabetes. In diabetic patients, atherogenic dyslipidemia significantly increases the risk of coronary artery disease and silent heart attack. 1  

Other potential risk factors of silent heart attack include being older, being overweight or obese, having high blood pressure, blood cholesterol, or blood glucose, and feeling stressed. People with prior heart attack or a family history of heart attack are also at higher risk of experiencing silent heart attack. 5

Eating cholesterol-, sugar-, salt-, and saturated fat-enriched unhealthy foods, not getting regular physical activity, and smoking habit are some of the major lifestyle risk factors of silent heart attack. 5

Women with a history of preeclampsia and individuals with a history of coronavirus disease 2019 (COVID-19) are at higher risk of experiencing silent heart attack. 5

Health consequences of silent heart attack   

Health consequences of silent heart attack depend on the risk factor profiles and comorbidities of affected patients. Patients with a history of stable angina (a type of chest pain) are at risk of experiencing the worst health consequences. 1

Patients with a documented silent heart attack are at significantly higher risk of cardiac death. In patients without coronary artery disease, silent heart attack increases the risk of adverse cardiovascular events and mortality. 1

A silent heart attack can increase the risk of heart failure by 35%. The risk is even higher in people aged below 50 years. Some preliminary data indicates that a silent heart attack may increase the risk of stroke. 6     

How to diagnose a silent heart attack

The signs and symptoms of a silent heart attack could be detected during physical examinations. Physicians may suspect an incidence of silent heart attack if the patient has a fast or uneven pulse rate. Unusual sound in the lungs is another parameter for suspecting a silent heart attack. 5

Tests that are commonly performed to diagnose silent heart attack include blood tests of cardiac biomarkers, electrocardiogram, cardiac catheterization with coronary angiography, computed tomography (CT) scan, magnetic resonance imaging (MRI), exercise stress test, nuclear stress test, and echocardiogram. 5

How to prevent a silent heart attack

The most effective medications to treat silent heart attack include beta-blockers and calcium channel blockers. Anti-platelet medicines such as aspirin and lipid-lowering medicines such as statin are also used to treat silent heart attacks. 1

In patients with coronary artery disease, behavioral stress management therapies have shown beneficial outcomes in terms of improving mental health and preventing silent heart attack. 1 

Coronary artery revascularization is not typically performed solely on the basis of silent heart attack symptoms. However, this procedure may provide beneficial outcomes in patients with high-risk characteristics, such as ischemia to a large myocardial region. 1   

The risk of having a silent heart attack can be reduced by considering some lifestyle changes, such as eating healthy foods, being physically active, reducing smoking and alcohol intake, managing stress levels, and maintaining healthy body weight.

References

1. Gul Z, Shams P, Makaryus AN. Silent Myocardial Ischemia. In: StatPearls. StatPearls Publishing; 2024. Accessed September 20, 2024. http://www.ncbi.nlm.nih.gov/books/NBK536915/

2. Cohn PF. Silent ischemia: a timely aspect in coronary artery disease. Herz. 1987;12(5):314-317. https://pubmed.ncbi.nlm.nih.gov/3315916/

3. The danger of “silent” heart attacks. Harvard Health. January 1, 2017. Accessed September 20, 2024. https://www.health.harvard.edu/heart-health/the-danger-of-silent-heart-attacks

4. 4 Silent Heart Attack Signs – Penn Medicine. Accessed October 5, 2024. https://www.pennmedicine.org/updates/blogs/heart-and-vascular-blog/2022/april/4-silent-heart-attack-signs

5. Does a Silent Heart Attack Have Symptoms? Cleveland Clinic. Accessed October 5, 2024. https://my.clevelandclinic.org/health/diseases/21630-silent-heart-attack

6. Silent heart attacks all too common, and often overlooked. www.heart.org. Accessed October 5, 2024. https://www.heart.org/en/news/2021/06/23/silent-heart-attacks-all-too-common-and-often-overlooked